Document gDb6d60M7a1VX0oEGJ9VKGk63

Fig. 1 S.P. 4 J.M. Extensive bilateral pleural calcification In former shipyard workers. Asympto- mafic. No part of pleura is immunecostal; diaphragmatic, mediastinal, pericardial. Bilateral calclfi-.: cation of this sort rarely seen except with prior asbestos exposure. Even'wives and children of the employed workers showed evidence of asbestos dis ease, indicating that exposure of lesser intensity might be seriously hazardous as well.11 RECENT SURVEY OF SHIPYARD WORKERS, GROTON, CONNECTICUT Cases of asbestos-associated disease among workers employed in a shipyard in Groton, in 1974-1975, were brought to our attention. Against the background ofwhat was already known concerning the poten tial for asbestos disease in shipyards, it appeared useful to obtain information concerning whether there was the likeli hood of a high incidence of such disease or whether the cases seen were isolated, random exceptions. Lung cancer, mesothelioma, extensive asbestosis and other serious complications of asbestos exposure are late findings. Limited X-ray change (parenchymal, with in the lung, or pleural) often precede these serious consequences. While such change may occur to an extent visible by X-ray without subsequent cancer or disabling asbestosis, their appearance among a group of workers provide evidence of prior significant asbetos exposure. Ab sence of such X-ray change is no guar-, antee that important asbestos exposure has not occurred. Many workers may have, had asbetos exposure sufficient to cause, death from mesothelioma, for example, without showing X-ray change. Neverthe less, taken as a whole, absence of X-ray change in a group of workers suspected qf: having been exposed to asbestos provides some evidence that the exposure was lim ited. On the other hand, the presence Of characteristic asbestotic X-ray abnormal ities is prima facie evidence that, overall, there was important asbestos exposure in the group. In light of this, we sought to ascertain whether there was significant prevalence of asbestotic X-ray abnormalities among Groton shipyard workers. Examinations HO 01 092 i CA-A CANCER JOURNAL FOR CLINICIANS Fig. 2J.B. Both flbrqtjp plaques and pleural Fig.;3 J.W- Age 49,1975. Truck driver.until: edification in x-ray of termer shipyard worker. .. .1969, wtteihhe became "pipe coverer In ashte- Asymptomatic. Thelr .presence ls merely evl- yard.' X-ray, flfteen years later, snows reticular . dence of prior asbestos exposure and not In- (Irregular) opacities of moderate profusion (2/2 dlcative that mesothelioma will necessarily In the (LO U/C Classification). Some shortness follow. of bfeath on exertion. Note: Infiltrate m tower lung fields, upper lobes clear. This Is common. were largely limited .to those whose em- . present in 274 of 636 workers with less ployment had begun 15 of more years be- than 20 years from onset of exposure (43.1 fore; all were volunteers.. A caveat is in .percent): and among 185 of 364 shipyard order: there is no way of knowing, under workers 20 or more years from onset (50.8 these circumstances, whether those who percent). Parenchymal disease was seen in volunteered were necessarily represen- 29,6 percent of the former group and 36.8 tative of the entire work force, or even of percent of the latter. Pleural changes tyere: their , specific employment category. Al- found in 23.1 percent of the less experi- together, 1,000 men were examined, in- enced workers and in 29.7 percent of the eluding 157 boilermqkers,>121 pipefitters, men with longer experience. The high 73 insulators, 82 painters, 69 carpenters, ; prevalence of pleural changes was not un- 117 welders, 104electricians, 108 outside expected, having been found previously machinists, as wetfsas laborers, molders, among shipyard workers in Britain and lead bonders, office workers, draftsmen, elsewhere.1* guards, and decontamination technicians. Thc importance of duration from on- Films were categorized using the Inter- setof exposure is clearly seen in Table 10, national Classification of Radiographs of where it is found that among 303 workers Pneumoconioses (QjQ U/C)(Appendix 1). who began work only in 1961 or later, 115 Overall, approximately half of the (38.0 percent) had abnormalities onX-ray. workers examined showed X-ray evidence,- In contrast, among 166 workers whose of pulmonary anid pleural changes of the employment began in 1950 or before, 85 sort regularly seen following direct or in- (51.2 percent) were abnormal, direct occupational exposure to asbestos No trade was immune to changes, (pulmonary asbestosis, pleural asbesto- Tbbles 11 and 12 indicate that this was as sis). The findings are outlined in Tables 9 true for painters as it was fpr electricians, and 10. One or another abnormality was for carpenters as for machinists, and for VOL.2B. NO. 2 MARCH/APRIL 1978 . 80.0) 09(1 j